A FUNDAMENTAL CONSIDERATION ON EVALUATING NOISE PRODUCED BY ROAD TRAFFIC CONTROLLED BY TRAFFIC SIGNALS

The actual road traffic noise that we encounter is affected by traffic signals. So, the random noise fluctuations usually exhibit periodic nonstationary properties caused by the periodic temporal change of traffic flow. Also, statistical parameters such as the equivalent sound level (Leq) and the median value of sound level (L50) are important for noise evaluation and regulation problems. In this paper, a new approximate probability density function (pdf) of nonstationary noise level fluctuation is proposed in a case where the road traffic flow is controlled by traffic signals, by paying special attention to the periodicity of fluctuation patterns of the cumulant statistics of noise level. Next, the explicit expressions of Leq and L50 are derived as an application of the above theory. The effects of the nonstationary properties caused by the traffic signals on the noise evaluation indices, Leq and L50, are shown quantitatively. Finally, statistical evaluation methods for the dispersion of Leq and L50 estimations caused by the finiteness of the sample sizes are theoretically considered, in a case when Leq and L50 for the periodic nonstationary road traffic noise are experimentally estimated by using the usual sound level meter and sampling methods. (A)

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  • Corporate Authors:

    Elsevier Science Publishers

    Crown House, Linton Road
    Barking, Essex IG11 8JU,   England 
  • Authors:
    • Yamaguchi, S
    • KATO, Y
    • ISHIHARA, S
  • Publication Date: 1994

Language

  • English

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Filing Info

  • Accession Number: 00663300
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Aug 24 1994 12:00AM